Worm-cutting attachment for gear-broaching machines



Aug. 5 1924.

J. 1.. PERKINS ET AL WORM CUTTING ATTACHMENT FOR GEAR BROACHING MACHINES Original Filed June 29 1921 )NVENToRs;

, n l i V/flll 1 n I I- ATTbRNEY.

Patented Aug. 5, 1924.

UNITED STATES JULIAN L. PERKINS, OF WEST SPRINGFIELD, AND FRANK W..SICKLES AND HIRAM D. CROFT, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNORS TO PERKINS APPLIANCE COMPANY, OF SPRINGFIELD. MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

WORM-CUTTING ATTACHMENT FOR GEAR-BRO'ACHING MACHINE-SJ Original application filed June 29, 1921, Serial No. 481,261. Divided and this application filed February 1, 1923. Serial No. 616,257.

To all whom it may concern:

Be it known that we, JULIA L. PERKINS, FRANK W. SICKLES, and HIRAM D. (how, all citizens of the United States of America,

said PERKINS being a resident of West Springfield, in the county of Hampden and State of Massachusetts, and said SmKLEs and CROFT being residents of Springfield, in said county and State, have invented a new and useful Worm-Cutting Attachment for Gear-Broaching Machines, of which the following is a specification,

Our invention relates to improvements in attachments for cutting worms, which attachments are for ear-broaching machines of the character 0 that which forms the subject matter of our Letters Patent of the United States, issued October 2, 1923, No. 1,469,602, of the application which eventuated in such patent this application is a division, and said invention consists generally of certain peculiar supporting means, work holding means, and driving mechanism for said last-named means, to-

gether with such other parts and members as may be necessary or desirable in order to render the attachment complete in every respect, all as hereinafter set forth.

The primary object of our invention is to provide the gear-breaching machine, which is the subject of the aforesaid application, with comparatively simple means or mechanism whereby worms may be cut and generated expeditlously, accurately, and economically on said machine, as well as spur, spiral,

and other gears.

A further object is to provide an attachment of this character which can be readil mounted on, secured to, and connected wit the gear-broaching machine, and as readily disengaged, disconnected, and removed therefrom.

Other objects and advantages will appear in the course .of the following description.

We attain the objects and secure the advantage of our invention by the means and mechanism illustrated in the accompanying drawings, in which- Figure 1 is a top plan, in partial section,

of an attachment WlllCh embodies a practical form of our invention; Fig. 2, a front-end elevation, in partial section, of the upper portion of a gear-broachin machine, such as that hereinbefore referrecf to, showing said attachment in place, and a worm blank in directly and closely associated with said. at-

tachment, are briefly described asfollows:

The frame of the machine is indicated by the numeral 1. At the front end of the frame 1 are bearings for a vertical Work shaft 2. A table 3 is provided at the front end of the frame 1. The frame 1 has a bed 4 behind the table 3. Mounted to slide longitudinally on the bed 4 is a carriage 5 Mounted for rotary adjustment in the front end of the carriage 5 is a cylindrical head 6, and this head has two forwardly-extending arms 7. The carriage 5 has at the front end a bearing-box 9 and a bearing-cap 10, bolted together on each side at 11, for the head 6. The work shaft 2 has at the upper end an enlargement 12 which is supported by and runs on a ball-bearing represented at 13, the latter being set into the top of the table 3. The shaft 2 immediately below the projection 12 and the ball-bearing 13 is journaled in that part of the frame 1 which forms the table 3, and said shaft is driven by means not shown herein, as also is the chain broach 8. In the top of the shaft 2 is an arbor 14.

A bevel-gear 15 is secured on the arbor 14 above the top of the shaft 2. This bevelgear is in, reality a part of the attachment.

The head 6 is arranged for rotary ad ustment in the front end of the carriage 5, and has a flange outside of such. end, said head being secured in place, after adjustment, by means of the bearing-cap 10 and the bolts 11. The bearing-box 9 and the bearing-cap 10 both have flanges at their front ends against which is received the flange of the head 6. A scale 16 is-provided on the peripher'y of the flange of the head 6 to coopof the links on each side of a unit, and through erate with an indicator point or mark suitably located on the adjacent bearing-box or bearing-cap flange, or for which point or mark may be used the upper surface of the bearing-box 9 which surface is adjacent to said scale. By means of the scale 16 and the associated indicator mark the amount of rotary adjustment given to the head 6 is determined.

. The arms 7, at the front end of the headbeing completed by means of additional caps 18 and bolts 19. Mounted on the shaft 17 is a pair of idlers 21, and mounted on the shaft 20 is a pair of notched driving-Wheels (not shown). The idlers 21 are spaced apart, as also are the aforesaid notched wheels, for the accommodation of the chain broach 8. On the front of the arms 7 are two chain-broach guides 22. These define the course of the chain broach 8 in its pas-,

sage through the cutting field. Each of the guides 22 is fastened, by means of a plurality of screws 23, to an inwardly-projecting part at the front end of one of the arms 7. Lateral slots 24 are formed in each guide 22 to accommodate the screws 23 and permit said guide to be adjusted toward and away links at each end, and a plurality of cutterbars 28 between said links, said cutter-bars being provided with teeth 29. In the presents example there are six cutter-bars 28 in each unit, and six teeth 29 on each cutter-bar. lhe row of teeth 29 on each cut ter-bar 28 is arranged at an angle to the sides of said bar, and the rows of teeth on the leading and following cutter-bars in the same line are continuous with said firstthe leading ends of the six cutter-bars 28 between said links in said unit. The pin projects at both ends beyond the two links connected thereby, and these projecting terminals are supported by and travel on the idlers and wheels which are mounted on the shafts 17 and 20.

WVhen in action the chain broach 8 moves upwardly behind the shafts 17 and 20 and the idlers and wheels mounted thereon, and downwardly in front of such parts.

With the exception of the bevel-gear 15 which is mounted on the arbor 14, the attachment is mounted on and secured to the table 3. A worm in a practically finished condition is represented at 30. a The attachment which is mounted on the table 3 is described as follows: i

A bracket 31 is bolted to the table 3 at the left-hand side thereof, and a housing 32 is bolted to said table at the right-handside thereof. The bracket 31 is provided with a bearing 33 in which is journaled a horizontal, transverse shaft 34, and which is further provided with a bearing 35 in which is journaled a horizontal, transverse, supplementary work shaft 36. The shaft 36 is behind the shaft 34. A. bevel-gear 37 and a spur gear 38 are secured to opposite terminals of the shaft 34, respectively at'the inner and outer ends of the bearing 33. The bevel-gear 37 intermeshes with and is driven by the bevel-gear 15. A spur'gear 39 is secured to the outer terminal of the shaft 36, and intermeshes with and is driven by the spur gear 38. The gear 39 is at the outer end of the bearing 35, and the shaft 36 is provided with a flange 40 which is at the inner end of said bearing.

The shaft 36 is provided with an arbor 41. 'The tapered terminal of the arbor 41 is received in the shaft 36 at the inner endthereof, and the opposite terminal of said arbor is received'in and supported by a bearing-block42, there being a lateral passage 43 in said block for the reception of said last-named arbor terminal. The housing 32 is completed by means of a cap-piece 44 that is bolted at 45 to a forwardly-projecting part of said housing. The bearing-block 42 is received in the housing 32 and secured therein by the cap-piece 44 when the bolt 45 is tightened. The arbor 41 has a flange 46 thereon adjacent to the shaft flange 40, and the worm blank is held tightly against the flange 46, so that said blank rotates with the shaft 36, by means of a nut 47 tapped onto the arbor 41 inside of the terminal portion thereof that is supported by thebearing-block 42, a washer 48 being interposed between said nut and the adjacent end of said blank.

The worm blank is mounted on the arbor 41 while the bearing-block 42 is out of position, or after the same has been removed from the housing 32. After placing the washer 48 and the nut 47 on the arbor 41, the bearing-block 42 is returned to place in the housing 32, and receives the adjacent terminal of the arbor 41 in the passage 43. Another method of procedure would be to place the blank in position on and remove it from the arbor 41 while the latter is disconnected from the shaft 36, it being necessary, as before, to take out the bearingblock 42, while said arbor is removed and replaced, and later to return said block.

In view of the fact that the bearing-block 42 is not a complete cylinder, it is necessary that the same be so placed every time in the housing 32 that the passage 43 will be in exact alignment with the axis of the shaft 36, and to this end a key 49 is provided, as shown in Fig. 3. The rear portion of the housing 32 when its cap-piece 44 and the bearing-block 42 are in a common vertical plane, which plane is a suflicient distance behind the passage 43 to afford the necessary amount of engagement between the parts, behind the vertical plane of said axis, to hold said block securely in place.

The width of the chain broach 8 must be equal to the length of the wormblank, in order that said broach shall act on said blank throughout its entire length during the cutting operation.

The head 6 is set, for cutting the worm 30, by adjusting said head about its axis until the angle of the chain broach equals the lead angle of the spiral tooth to, be cut, plus the lead angle of said broach, or minus the lead angle of said broach, if the lead of said tooth be in the opposite direction. In the example herein shown it is assumed that a right-hand lead is to be given to the worm.

In practice, the worm blank is driven from the shaft 2 and the arbor 14-through the medium of the bevel-gears 15 and 37, the shaft 34, the gears 38 and 39, the shaft 36, and the arbor 41, and the carriage 5 is advanced to carry the forward reach of the moving chain broach 8 into contact with said blank, andinto the latter tothe extent required. As the chain broach travels down through the revolving work and is advanced toward the axis of said work, a spiral tooth is cut and developed throughout its entire length, and with all of its convolutions uni- Iorm and accurate, so that at the end of the cutting operation a completely finished worm is produced. After the worm has been completed, the carria e 5 is retracted, and said worm is remove from the arbor made without. departing from the spirit of our invention or exceeding the scope of what is claimed.

What we claim as our invention and desire to secure by Letters Patent, is

1. The combination in a flexible cutting element capable of passing an uninterrupted succession of teeth through the cutting field of a gear-broaching machine, of means to support and continuously rotate work on an axis which is in angular relationship to that portion of said cutting element which passes through the cutting field, and in operative position relative to said element. the width of the latter being approximately equal to the length of said work.

2. The combination with a flexible cutting element capable of passing an uninterrupted succession of teeth through the cutting field of a gear-broachihg machine, of means to support and continuously rotate work on a horizontal axis in operative position relative to said cutting element. the width of the latter being approximately equal to the length of said work.

3. The combination with a reciprocating carriage, a head mounted in said carriage, a flexible cutting element capable of passing an uninterrupted succession of teeth through the cutting field, said cutting element being carried by said head, and a continuously-revolving work shaft, of a gear-broaching machine, the direction longitudinally of said shaft corresponding generally with the direction of that portion of said element which is in said field at any given time, of a work arbor and supporting means therefor, said arbor being approximately at right-angles to said shaft, and 111831151110 drive said arbor from said shaft.

4. The combination with a reciprocating carriage, a head mounted in said carriage, a flexible cutting element capable of passing an uninterrupted succession of teeth through the cutting field, said cutting element being carried by said head, a continuously-rotating work shaft extending lengthwise in the same generaldirection as that portion of said element which is in said field at any given time, and an arbor in said shaft, of a gearrbroaching machine, of a work arbor and supporting means therefor, said lastnamed arbor 'being approximately at rightangles to said shaft and first-named arbor, and means to drive said last-named arbor from said first-named arbor.

5. The combination with a flexible cut ting element capable of passing an uninterrupted succession of teeth through the cuttin field, a table, and a continuously-rotating work shaft having one terminal located in said table, of a gear-breaching machine, of a bracket mounted on said table, shafts journaled in said bracket, and means to drive said shafts from said work shaft,

ing gears, and the former being also provided with a bevel-gear which. intermeshes with said first-named bevel-gear, and a work arbor supported by said rear shaft.

7. The combination, with a flexible cutting element capable of passing an uninterrupted succession of teeth through the cutting field, a table, and a' continuously-rotating work shaft having the upper terminal.

thereof located in said table, of a gearbroaching machine, and a bevel-gear connecte'd with such terminal, of a bracket mounted on said table, front and rear shafts journaled in said bracket and provided with intermeshing gears, said front shaft also being provided with a bevel-gear that intermeshes with said first-named bevel-gear, a work arbor carried at one terminal of said rear shaft, and means to support the other terminal of said arbor.

8. The combination with a cutting element which continuously asses through the cutting field, a table, an continuously-rotating Work shaft having the upper terminal located in said table, of a gear-broaching machine, and a bevel-gear connected with such terminal, of a bracket mounted on said table, front and rear shafts journaled in said bracket andprovided with intermeshing gears, said front shaft also being provided with a bevel-gear that intermeshes with said first-named bevel-gear, a work arbor havin one terminal connected with said rear shaft, and a removable block to center and support the other terminal of said arbor, said block being carried by said bracket.

9. The combination with a cutting element which continuously passes through the cutting field, a table, and a continuously-rotating WOIk shaft having the upper terminal located in said table, of a gear-broaching machine, and a bevel-gear connected with such terminal, of a bracket and a housing mounted on said table, front and rear horizontal shafts journaled in said bracket and provided with intermeshi'ng gears, said front shaft also being provided with a bevelear that intermeshes with said firstname bevel-gear, a work arbor having one terminal connected with said rear shaft, a centering. and supportin block for said arbor atthe other termina said block being seated in said housing, and a cap-piece and bolt to retain said block in place.

JULIAN L. PERKINS. FRANK W. SICKLES HIRAM D. CROFT. Witnesses:

F. A. CUTTER. C. C. WEST. 

